PROBLEM 25.18 - Organic Chemistry

Question

Question: Write out steps to show how each of the following pairs of compounds can be separated by an extraction procedure.

a.   

and

b.

and

Step-by-Step Solution

Answer

Answer

a.

b.

Separation of the amine compound

An amine can be separated from other organic compounds by converting it to a water-soluble ammonium salt by an acid-base reaction. In each case, the extraction procedure will employ the following steps: 

 

• Dissolve the amine and either X or Y in CH₂Cl₂ . 
• Add a solution of 10% HCl. The amine will be protonated and dissolved in the aqueous layer, while X or Y will remain in the organic layer as a neutral compound. 
• Separate the layers.

 

Explanation

a. The salts are soluble in water, and the non-polar compounds are insoluble in water.

The reaction is shown as follows.

Solubility of the products in the respective solvents

b. The tertiary amine forms a salt. The higher ether compounds are insoluble in water.

Solubility of the products in the respective solvents